Graeme, the analog meter at Dick Smith's is the analog RadioShack meter. In the past I used both the analog and digital RS meters that colleagues had and found the digital meter to clearly be more useful, so I bought one. Numbers are easier to read than a moving needle and additional measurement modes, particularly a max/min measurement, are available. The digital RS meter apparently isn't sold directly in Australia and the one available at Dick Smith's advertises a measurement range of 300-6000Hz. If correct this would make it less suitable for audio purposes, although that range is appropriate for measuring hearing damage possibility in the workplace.
This unit for AU$99.95 would appear to be more suitable, judging solely from the written description(I have no knowledge of it).
An SPL meter is nice to have for seeing what sound levels that you're actually working with, but for simply calibrating speaker levels the built-in meter in the Yamaha and many other receivers does a fine job, so you might try that first, even as to the two sub calibration.
